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 * Author: Eitan Marder-Eppstein
 *         David V. Lu!!
 *********************************************************************/
#ifndef _DIJKSTRA_H
#define _DIJKSTRA_H

#define PRIORITYBUFSIZE 10000

#include <math.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <global_planner/planner_core.h>
#include <global_planner/expander.h>

// inserting onto the priority blocks
#define push_cur(n)  { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ && currentEnd_<PRIORITYBUFSIZE){currentBuffer_[currentEnd_++]=n; pending_[n]=true; }}
#define push_next(n) { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ && nextEnd_<PRIORITYBUFSIZE){nextBuffer_[nextEnd_++]=n; pending_[n]=true; }}
#define push_over(n) { if (n>=0 && n<ns_ && !pending_[n] && getCost(costs, n)<lethal_cost_ && overEnd_<PRIORITYBUFSIZE){overBuffer_[overEnd_++]=n; pending_[n]=true; }}

namespace global_planner
{
class DijkstraExpansion : public Expander
{
public:
    DijkstraExpansion(PotentialCalculator *p_calc, int nx, int ny);

    virtual ~DijkstraExpansion();

    bool calculatePotentials(unsigned char *costs, double start_x, double start_y, double end_x, double end_y,
                             int cycles, float *potential);

    /**
     * @brief  Sets or resets the size of the map
     * @param nx The x size of the map
     * @param ny The y size of the map
     */
    void setSize(int nx, int ny); /**< sets or resets the size of the map */

    void setNeutralCost(unsigned char neutral_cost)
    {
        neutral_cost_ = neutral_cost;
        priorityIncrement_ = 2 * neutral_cost_;
    }

    void setPreciseStart(bool precise) { precise_ = precise; }

private:

    /**
     * @brief  Updates the cell at index n
     * @param costs The costmap
     * @param potential The potential array in which we are calculating
     * @param n The index to update
     */
    void updateCell(unsigned char *costs, float *potential, int n); /** updates the cell at index n */

    float getCost(unsigned char *costs, int n)
    {
        float c = costs[n];
        if (c < lethal_cost_ - 1 || (unknown_ && c == 255))
        {
            c = c * factor_ + neutral_cost_;
            if (c >= lethal_cost_) c = lethal_cost_ - 1;
            return c;
        }
        return lethal_cost_;
    }

    /** block priority buffers */
    int *buffer1_, *buffer2_, *buffer3_; /**< storage buffers for priority blocks */
    int *currentBuffer_, *nextBuffer_, *overBuffer_; /**< priority buffer block ptrs */
    int currentEnd_, nextEnd_, overEnd_; /**< end points of arrays */
    bool *pending_; /**< pending_ cells during propagation */
    bool precise_;  // 是否精确的
    /** block priority thresholds */
    float threshold_; /**< current threshold */
    float priorityIncrement_; /**< priority threshold increment */

};
} //end namespace global_planner
#endif
